Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) ==========================================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) Interface for registering and calling firmware-specific operations for ARM
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3) ==========================================================================
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5) Written by Tomasz Figa <t.figa@samsung.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7) Some boards are running with secure firmware running in TrustZone secure
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8) world, which changes the way some things have to be initialized. This makes
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) a need to provide an interface for such platforms to specify available firmware
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) operations and call them when needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) Firmware operations can be specified by filling in a struct firmware_ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) with appropriate callbacks and then registering it with register_firmware_ops()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) function::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 	void register_firmware_ops(const struct firmware_ops *ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) The ops pointer must be non-NULL. More information about struct firmware_ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) and its members can be found in arch/arm/include/asm/firmware.h header.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) There is a default, empty set of operations provided, so there is no need to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) set anything if platform does not require firmware operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) To call a firmware operation, a helper macro is provided::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 	#define call_firmware_op(op, ...)				\
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) the macro checks if the operation is provided and calls it or otherwise returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) -ENOSYS to signal that given operation is not available (for example, to allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) fallback to legacy operation).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) Example of registering firmware operations::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) 	/* board file */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) 	static int platformX_do_idle(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 		/* tell platformX firmware to enter idle */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	static int platformX_cpu_boot(int i)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 		/* tell platformX firmware to boot CPU i */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 		return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	static const struct firmware_ops platformX_firmware_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 		.do_idle        = exynos_do_idle,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 		.cpu_boot       = exynos_cpu_boot,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 		/* other operations not available on platformX */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	};
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 	/* init_early callback of machine descriptor */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 	static void __init board_init_early(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 	{
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		register_firmware_ops(&platformX_firmware_ops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) Example of using a firmware operation::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 	/* some platform code, e.g. SMP initialization */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 	__raw_writel(__pa_symbol(exynos4_secondary_startup),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		CPU1_BOOT_REG);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 	/* Call Exynos specific smc call */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	if (call_firmware_op(cpu_boot, cpu) == -ENOSYS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 		cpu_boot_legacy(...); /* Try legacy way */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) 	gic_raise_softirq(cpumask_of(cpu), 1);